The present invention relates to a retractable antenna for a portable radio communication apparatus and, more particularly, to a structure for allowing the antenna to be extended from and retracted into the casing of the apparatus at the outside of said casing.
It has been customary with an antenna of the kind described to hold the casing of a portable radio communication apparatus by one hand and extend or retract the antenna by nipping the tip of the antenna by the other hand. The antenna is provided with a round metallic feed point at the innermost end thereof, and a projection inboard of the feed point. The antenna is guided into and out of the casing by an antenna guide. A flexible metallic contact is affixed to the top of the casing. When the feed point of the antenna is brought into contact with the metallic contact, a carrier coming in through the antenna is delivered to a receiver section built in the casing.
When the antenna is extended from the casing, the feed point of the antenna forces the flexible metallic contact to open. When the projection of the antenna abuts against the contact, the feed point is locked. To retract the antenna into the casing, the antenna is pushed into the casing along the antenna guide with the result that the flexible metallic contact is restored to the original position.
A structure for mounting a retractable antenna of the type described is disclosed in, for example, Japanese Utility Model Laid-Open Publication No. 2-123103 (Oct. 9, 1990). The structure taught in the Laid-Open Publication includes a curved guide in order to surely receive an antenna in a casing, thereby eliminating noise due to vibration or similar cause.
In the conventional structure described above, when the antenna is extended from the casing, it is locked by the engagement of the metallic contact of the casing and the feed point of the antenna. This brings about a problem that the user of the apparatus has to nip the tip of the antenna and pull it out with one hand while holding the casing with the other hand. Specifically, when the user is holding, for example, baggage with one hand, the user cannot extend the antenna from the casing.